1H-Pyrazole-5-carboxylic acid, 3-bromo-1-(3-chloro-2-pyridinyl)-

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

3-15-2006 to 318-2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well documented, GLP and OECD 201 guideline study.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

Remarks:

The study was conducted according to the guideline in effect at time of study conduct.

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

Remarks:

The study was conducted according to the guideline in effect at time of study conduct.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

DBC80

IUPAC Name:

DBC80

Constituent 2

Reference substance name:

-

EC Number:

481-150-8

EC Name:

-

Cas Number:

500011-86-9

Molecular formula:

C9H5BrClN3O2

IUPAC Name:

3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylic acid

Constituent 3

Reference substance name:

1H-Pyrazole-5-Carboxylic Acid, 3-Bromo-1-(3-Chloro-2-Pyridinyl)-

IUPAC Name:

1H-Pyrazole-5-Carboxylic Acid, 3-Bromo-1-(3-Chloro-2-Pyridinyl)-

Details on test material:

- Name of test material (as cited in study report): IN-CBD80
- Molecular formula: C9H5BrCIN3O2
- Physical state: Tan powder
- Analytical purity: 96.75
- Lot/batch No.: 008
- Expiration date of the lot/batch: 7/22/08
- Stability under test conditions: Stable
- Storage condition of test material: Stored in the dark at room temperature.
- Other: Supplied by DuPont Company, Stine- Haskell Research Center Crop Protection Products, Newark, Deleware.

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: High and low concentrations, positive and negative controls.
- Sampling method: Collected in glass containers at the beginning and end of the study.
- Sample storage conditions before analysis: Not specified, sent to Department of Analytical Chemistry for analysis.

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Controls: Negative and vehicle controls.
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Acetone
- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)): <0.1 mL/L
- Evidence of undissolved material (e.g. precipitate, surface film, etc): No

Test organisms

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchneriella subcapitata
- Source (laboratory, culture collection): In-house culture, original source Marinco Bioassy Laboratory.
- Age of inoculum (at test initiation): 3 days

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

None

Test conditions

Hardness:

Not applicable

Test temperature:

20.9-23.6° Celcius

pH:

8.01-9.54

Dissolved oxygen:

Not applicable

Salinity:

Not applicable

Nominal and measured concentrations:

Nominal- Control, Vehicle control, 3.5, 6.3, 11.4, 20.6, 37.1, 66.7, and 120 mg/L.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): Closed, with non-absorbant cotton plugs.
- Material, size, headspace, fill volume: Glass 250 mL conical flasks, 100 mL fill volume
- Initial cells density: 71667 cells/mL
- Control end cells density: 1,876,667 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3
- No. of vessels per vehicle control (replicates): 3


GROWTH MEDIUM
- Standard medium used: yes



TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Distilled water
- Culture medium different from test medium: no


OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: yes, to 8.1 with 0.1 N HCl or 0.1 N NaOH
- Photoperiod: Continuous
- Light intensity and quality: 7900-7985 lux


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Growth rate and percent inhibition, at 0, 24, 48 and 72 hours.
- Determination of cell concentrations: Visual count using an Improved Neubaur Haemocytometer and microscope.


TEST CONCENTRATIONS
- Range finding study concentrations: 15, 30, 60 and 120 mg/L
- Results used to determine the conditions for the definitive study: Yes

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

other: EyC50

Effect conc.:

54.49 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

cell number

Remarks on result:

other: 95% CL 54.063-54.917 mg/L

Effect concentrations 2

Duration:

72 h

Dose descriptor:

other: ErC50

Effect conc.:

> 120 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

< 3.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

cell number

Effect concentrations 4

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

6.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

- Exponential growth in the control (for algal test): yes

Results with reference substance (positive control):

- Results with reference substance valid? Yes

Reported statistics and error estimates:

EyC50 and ErC50 were calculated using regression equations. NOEC Confidence limits were calculated using NCSS 2000, and Duncan's Multiple Comparison Test.

Applicant's summary and conclusion

Conclusions:

The 72 hour 50% yield inhibition concentration of IN-DCB80 to P. subacapitata is 54.49 mg/L, with 95% confidence limits of 54.063-54.917 mg/L, and a NOEC of 3.5 mg/L. The 72 hour 50% rate inhibition concentration of IN-DCB80 to P. subcapitata is > 120 mg/L, with a NOEC of 6.3 mg/L.